Pulsed Laser Deposition of SiO₂Thin Films with Dimethylpolysiloxane Targets

Abstract

SiO2 thin films were deposited at room temperature by 193-nm ArF excimer laser ablation of dimethylpolysiloxane in oxygen atmosphere. Only the side chains (–CH3) of the target were photodissociated during ablation to deposit Si–O bonds on a substrate in a high laser fluence of about 10 J/cm2. Oxygen gas worked to oxidize the Si–O bonds ejected from the target to form SiO2 thin films at the gas pressure of 4.4×10-2 Torr, in addition to reducing the isolated carbon mixed into the films. The transmittance of the 400-nm-thick films was 95% at a 500 nm wavelength. The refractive index of the films was defined as 1.416 at a wavelength of 633 nm. The chemical composition was also confirmed to be SiO2 by X-ray photoelectron spectroscopy. No smooth and dense film was observed by a scanning electron microscope. Electrical resistivity of 107 Ωm was obtained.